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How to Manage Pests

The UC Guide to Healthy Lawns

Perennial ryegrass — Lolium perenne

Photo of perennial ryegrass


Perennial ryegrass is a very competitive cool-season grass, best adapted to coastal regions that have moderate temperatures throughout the year. It prefers full sun but will tolerate partial shade. Perennial ryegrass has the highest wear-tolerance of any cool-season grass and can tolerate high traffic. It is often used around homes, schools, and parks. Because it germinates quickly, it is often used for overseeding winter-dormant bermudagrass lawns. Its rapid emergence helps to suppress weeds. For a more traffic and disease-resistant turf, it is often mixed with Kentucky bluegrass.

Identifying tips

A fine-textured, rich green grass with the leaf folded in the bud. Leaf margins are parallel, the back of the leaf is shiny, and the tips of the leaf blades are tapered. The collar usually has outgrowths (auricles) that clasp the stem. Ryegrass may form clumps where marginally adapted. There are no rhizomes or stolons. Perennial ryegrass has a bunchgrass-type growth habit.


Moderate to high maintenance. It has a moderately low tolerance for heat, shade, and drought and a high tolerance for cold temperatures.

Illustration of collar region perennial ryegrass
Collar of perennial ryegrass
Illustration of overall plant of perennial ryegrass
Overall plant structure of perennial ryegrass

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